wikimedia/mediawiki-core

<?php

namespace MediaWiki\User\TempUser;

use UnexpectedValueException;
use Wikimedia\Rdbms\LikeValue;
use Wikimedia\Rdbms\Platform\ISQLPlatform;

/**
 * Helper for TempUserConfig representing string patterns with "$1" indicating
 * variable substitution.
 *
 * @internal
 */
class Pattern {
    /** @var string */
    private $debugName;
    /** @var string */
    private $pattern;
    /** @var string */
    private $prefix;
    /** @var string */
    private $suffix;

    /**
     * @param string $debugName The name of the pattern, for use in error messages
     * @param string $pattern The pattern itself
     */
    public function __construct( string $debugName, string $pattern ) {
        $this->debugName = $debugName;
        $this->pattern = $pattern;
    }

    /**
     * Does the pattern match the given name?
     * @param string $name
     * @return bool
     */
    public function isMatch( string $name ) {
        $this->init();
        $match = true;
        if ( $this->prefix !== '' ) {
            $match = str_starts_with( $name, $this->prefix );
        }
        if ( $match && $this->suffix !== '' ) {
            $match = str_ends_with( $name, $this->suffix )
                && strlen( $name ) >= strlen( $this->prefix ) + strlen( $this->suffix );
        }
        return $match;
    }

    /**
     * Substitute the serial number into the pattern.
     *
     * @param string $mappedSerial
     * @param ?string $year
     * @return string
     */
    public function generate( $mappedSerial, ?string $year = null ) {
        $this->init();
        return $this->prefix .
            ( $year ? $year . '-' : '' ) .
            $mappedSerial .
            $this->suffix;
    }

    /**
     * Convert the pattern to an SQL like clause
     *
     * @deprecated since 1.42. Use toLikeValue() instead
     * @param ISQLPlatform $db
     * @return string
     */
    public function buildLike( ISQLPlatform $db ) {
        wfDeprecated( __METHOD__, '1.42' );
        $this->init();
        return $db->buildLike(
            $this->prefix,
            $db->anyString(),
            $this->suffix
        );
    }

    /**
     * Convert the pattern to an SQL builder "LIKE" value that matches it
     *
     * @param ISQLPlatform $db
     * @return LikeValue
     */
    public function toLikeValue( ISQLPlatform $db ): LikeValue {
        $this->init();
        return new LikeValue(
            $this->prefix,
            $db->anyString(),
            $this->suffix
        );
    }

    /**
     * Extract the variable part of the string (matching $1 or YYYY-$1),
     * or null if there is no match
     *
     * @param string $name
     * @return ?string
     */
    public function extract( string $name ) {
        if ( $this->isMatch( $name ) ) {
            return substr( $name,
                strlen( $this->prefix ),
                strlen( $name ) - strlen( $this->prefix ) - strlen( $this->suffix ) );
        }
        return null;
    }

    /**
     * Initialise the prefix and suffix
     */
    private function init() {
        if ( $this->prefix === null ) {
            $varPos = strpos( $this->pattern, '$1' );
            if ( $varPos === false ) {
                throw new UnexpectedValueException( __CLASS__ .
                    "pattern {$this->debugName} must be of the form \"prefix \$1 suffix\"" );
            }
            $this->prefix = substr( $this->pattern, 0, $varPos );
            $this->suffix = substr( $this->pattern, $varPos + strlen( '$1' ) );
        }
    }
}